Pipelines don't rupture around here and I've lost electricity for a total of just a few hours in the past 18 years. If there are power lines down somewhere there's usually just a blink when it's rerouted. If a pipeline ever does rupture I have a propane heater and camping stove. I can fire them both up and I have enough propane to last a week. I'll sit here in my arctic clothing and only run the heat for 5 minutes at a time if it looks like a permanent situation.
When the SHTF nothing is certain!
We have four diesel generators for our community, and they are large enough to energized the entire city (2,000 people and four large industries). We maintain 10,000 gallons of diesel in our own tank, plus we have a contract with the local supplier for another 40,000 gallons "on demand." This is done to meet our contracts with our main electric supplier and governmental requirements.
We typically run thirty days per year (one month if done continuously). The reasons for these "runs" are storm damage to infrastructure supplying our community and peak loads that the large generation facilities can not meet. Our community has never faced a long term blackout or brownout, because we maintain these generators and what it takes to run them.
Sadly, I do not live in town. I have a small generator and fuel supply to carry us through for about a week in "conservation" mode.
Bottom line - If you have a generator because you don't or can't trust the grid, you also need to realize that the fuel supply cannot be trusted either, so you must have a way to store a supply. Don't forget to exercise your generator and keep your fuel fresh.